Pumps and Systems Info from the Experts at KNF

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KNF’s new FK 1100 diaphragm liquid pump is one of the most advanced solutions on the market for gentle, low-pulsation flow. The 12 L/min flow rate doubles KNF’s previous maximum for liquid diaphragm pumps. This pump is robust, adjustable, and offered in a variety of application-friendly materials.

The FK 1100 has only one inlet and one outlet, despite having three diaphragms. These are offset by 120° from each other while connected in parallel, resulting in very low pulsation and minimal shear forces. Intensive testing has proven that the pump easily achieves pulsation values below 200 mbar at the inlet and outlet. This gentle conveyance spares fragile system components and media elements from potential damage.

The pump has a highly durable design with a die-cast aluminum housing and high-torque motor options that provide continuous operation with up to 87 psig back pressure. Even at this high pressure, the FK 1100 still delivers an impressive 8 L/min.

This pump is self-priming with a 13.5 inHg suction height. It is also able to run dry which reduces the need for additional equipment, offers more flexibility in planning, and allows for faster and easier system integration.

Versions are available in a variety of carefully selected materials, such as NSF-certified materials for food applications and chemically resistant elastomers. Customers can also choose between different drives, such as brushless DC or single-phase AC motors. The speed of the brushless DC motor can be controlled using analog or digital PWM signals, permitting lower flow rates if desired.

New product is designed for recirculation applications in a diverse set of markets

The FP 400 is a next-generation diaphragm pump from KNF. It combines the traditional advantages of diaphragm pump technology — self priming, the ability to run dry, and long, maintenance-free lifetime under continuous-operation conditions — with a pulsation level comparable to gear pumps.

Pulsation for new FP 400 is less than 150 mbar. Levels far below this are achievable, depending on system tubing hardness, tubing inside diameter, and flow path length/configuration. The pump delivers up to 5 L/min of liquid at back pressures to 15 psi, with complete linear control of flow between 10% and 100% of the nominal flow rate. Pump flow is fully stable with fluid viscosities ranging between 1 and 150 cSt. The pump handles viscosities up to 500 cSt with some flow rate reduction.

KNF designed the FP 400 specifically to provide gentle, low-shear conveyance of sensitive media. Other strengths of this innovative new pump include very low vibration, a noise level below 55 dBA, chemically resistant flow path material options for use with aggressive media, and an IP65 protection rating.

The many benefits of FP 400 make it particularly well suited for recirculation applications in a diverse set of markets, including:

KNF has introduced new micro gas pump NMP830 HP for OEM customers. This new diaphragm pump offers outstanding high flow, pressure, and suction performance in a compact size. It is ideal for medical therapy, monitoring, and reprographic applications.

Compact NMP830 HP measures just 31mm (1.25”) in width. Yet it produces free flow up to 5.5 L/min with a single head design and to 10 L/min with a dual head. Furthermore, this pump produces best-in-class pressure of up to 3.0 bar g (43.5 psig) and vacuum down to 50 mbar absolute (28.4 inHg).*

The new NMP830 HP is an extension of KNF’s NMP series. This latest addition to the line offers a 33 – 44% increase in flow-to-size ratio compared to existing NMP850 and NMP830 models, respectively. Vacuum and pressure performance are also significantly improved at a comparatively smaller size and lower weight.

Thanks to its compact size, high performance, and quiet operation, the NMP 830 HP pump is particularly well-suited for use in patient monitoring, wound and compression therapy, and respiratory care devices. Additional applications that will benefit from the pump’s features include environmental and security monitors, inkjet printing and color printers/plotters, lab equipment, fuel cell technology, and more.

Available with brushed and 2- or 4-wire brushless DC motors. Standard offerings include EPDM and PPS wetted components. All KNF pumps are engineered for success by optimizing pump solutions to meet customer’s specific requirements.

Liquid pumps made by pump technology leader KNF were on board an HTV-7 unmanned cargo spacecraft launched from Japan on September 23, 2018. Destined for the International Space Station (ISS), the spacecraft and its vital payload successfully docked three days later.

KNF’s first ever space-worthy liquid pumps are part of a new Life Support Rack for the International Space Station. Also known as an Advanced Closed Loop System (ACLS), the rack purifies air and produces oxygen for the ISS. It was developed by Airbus Defence and Space for the European Space Agency (ESA).

Engineers at KNF Flodos AG in Switzerland worked with Airbus for four years to specify and design the pump, which is based on KNF’s proven FEM 1.09 dosing pump. The project was part of Airbus’s COTS (commercial off-the-shelf) program, which uses well-established components to reduce the price tag for space flight.

The new ACLS rack will be installed in the ISS’s Destiny module (also known as the US Lab) by ESA astronaut and ISS commander Alexander Gerst on November 2, 2018. The technology is critical for achieving the closed loop life support system necessary for human space flight beyond low Earth orbit.

The two KNF pumps form part of an electrolyzer that produces oxygen and hydrogen from water. The pumps transfer supply water from a plastic bag into the ACLS, a key job since the oxygen produced is used to replenish the cabin air. The ACLS uses a Sabatier reactor to further increase system efficiency and reduce water consumption on the station.

According to the Senior Engineer at KNF Flodos in Switzerland, this was a unique and exciting opportunity for the engineering team. “Complying with the specifications for the COTS program was an interesting and challenging task. We had to keep the key components of the standard FEM 1.09 pump to ensure it maintained its reliability and specifications but make significant design modifications.”

The new, space-worthy KNF pump features several adaptations to the pump exterior, including:

Stainless steel housing

Vacuum-rated ball bearings

Stainless steel fittings for the fluid connections

Integration of a space-rated drive motor (which had to be achieved within a very short timeframe).

KNF is proud to have taken part in this project with Airbus Defense and Space and to prove that KNF was able to provide a solution for this demanding application.

TIPS FROM THE SERVICE BENCH

Phillips and Allen have dominated machine, sheet metal and cap screws for a long time. They are popular, easy to use and easily recognizable. But Phillips and Allen are looking over their shoulders! There are a couple of New Kids on the Block!

The new kids’ names are Torx and Pozidriv. The names may sound foreign but they fit right in the machine screw neighborhood. More surface area and better geometry make these screws more resistant to cam-out — or stripping — as it is more widely known. KNF is still utilizing Phillips and Allen head screws but Torx and Pozidriv are definitely making their presence felt.

TORX

Figure #1 (click to enlarge)

Torx are called “star drive” by some, as the recess resembles a 6 pointed star. The six points of contact engagement allows for higher torque being applied than a conventional Allen hex drive of the same size. Torx sizes are denoted by a T, followed by a number from 1 to 100. Common sizes used for KNF products include T6, T10, T15, and T25.

POZIDRIV

Figure #2 (click to enlarge)

Pozidriv screws are almost a cousin to Phillips. The Pozidriv (sometimes spelled incorrectly as “Pozidrive”) is actually an improved version of the Phillips screw drive. The name is short for Positive Drive. This screw recess is very easy confused with Phillips if not noticed. Using a Phillips driver for Pozidriv screw recesses can easily result is a stripped head due to the different geometry of the driver itself. The Pozidriv has additional ribs in the driver tip which are received by the secondary web of the Pozidriv screw itself. This extra feature provides more turning strength due to the higher tool engagement. Figure #2 show various Pozidriv screws and drivers; shown clockwise (from top-left): Pozidriv screw heads, Pozidriv handles, Pozidriv driver, black &amp; white image of Pozidriv.

Pozidriv drive bits are designated by the letters “PZ” plus a size code of 0, 1, 2, 3, 4 or 5. Common at KNF are the 0, 1, and 2 sizes. The drivers themselves will have a PZ marking and size code, and possibly the Pozidriv image on the handle butt.

The Pozidriv screws are visually distinguishable from Phillips by a set of radial indents set at 45° from the main cross recess on the head of the screw. These markings are sometime hard to see on plated or treated screws as the treatment may fill in the slighter 45 degree markings.

Please take care to look at these screws carefully before removing for service. Using the right driver will make your servicing quick and efficient. If you are in doubt of which screw is used on your KNF pump, please contact us. We are here for you.

WELCOME TO THE NEIGHBORHOOD

They don’t make things the way the used to, and this can be a good thing, since the latest tools usually incorporate technological advances that improve performance. Please give the “New Kids on the Block” a chance, they are proving to be hard workers!

On February 4, 2005, KNF USA engineers entered the temperature-controlled space of the “Life Test Room” in Trenton, NJ to initiate prototype testing for a specially-modified version of the KNF N 838 series diaphragm pump. At the time, the custom-designed OEM vacuum pump was being developed for a Fortune 100 medical device manufacturer, as an integral component of their immunoassay and clinical chemistry analyzer. The KNF pump would need to perform its duty – vacuum aspiration of biological samples – quickly and quietly, while ensuring precision and durability over the life of the pump. Like all spec-driven KNF project pumps, the custom-engineered N 838 vacuum pump was to undergo substantial testing to ensure accuracy, reliability, and overall quality.

A peek inside the carefully controlled conditions of KNF’s Life Test Room

Among all tests performed by the KNF R&D team, the Life Test may be the most valuable as it simulates the rigorous operating conditions often found in real-world environments – providing valuable data which is used to further improve pump performance. KNF pumps that undergo this particular test are operated under a continuous duty cycle, at high load, in unfavorable temperatures. Collectively, these test settings amount to what KNF Engineers use to determine a “worst case scenario”. In short, the Life Test is employed as a means to identify specific opportunities for improvement, while simultaneously gauging the life span of the pump in its current configuration.

The specially-modified version of KNF’s N 838 diaphragm vacuum pump has been running in a controlled test environment since Feb. 4, 2005.

Remarkably, from the date this post is written, over 12 years (105,189 hours) have passed since Life Testing began for this special N 838 project pump. You read that correctly; the incredibly durable N 838 pump is still running strong after more than a decade! This impressive test run time represents the longest continuous duty timeframe ever recorded at KNF Neuberger. It should also be noted that this record-setting operating life was achieved with only a few minor updates including diaphragm replacements at 30K and 60K hours. Despite advancements in both pump technology and testing procedures, engineers at KNF will continue to operate this extraordinarily resilient pump, in the Life Test Room, until it has completed a full lifetime…whenever that may be.

To put this unbelievable achievement into perspective, we have compiled a list of historical events* that have occurred since the start of the N 838 project pump Life Test:

Tips From the Service Bench

When pumping liquids, you must be sure flow path wetted materials are compatible with intended media. If not researched and tested, issues may arise in the field that may impact product life and maintenance schedules.

While Chemical Compatibility Charts are a good place to start your research, there is typically a standard disclaimer at the bottom that limits their application and places the responsibility on you the buyer, such as:

Warning: The information in this chart is to be used as a guide, ONLY. Although believed to be accurate, actual decisions on material selection need to be thoroughly tested and evaluated by the customer for each specific application. It is the full responsibility of the customer to perform and evaluate the compatibility of materials for their specific requirements. The manufacturer takes no responsibility, etc., etc…

ARE WE COMPATIBLE?

Polymer components exposed to incompatible media can experience swelling or loss of physical properties. When severe, these effects can lead to degradation of pump performance, reduced pump life, leakage, and even pump failure. These issues are avoided with proper material selection. Many pump manufacturers provide a selection of flow path materials to meet most needs, and some provide additional material options for exceptional cases.

TESTING OUR RELATIONSHIP

So, how do you go about testing chemical compatibility? You can get test swatches of possible polymer materials. But, results using test swatches can be less than applicable since they may be much thinner or thicker than the actual parts used in pumps. KNF offers a better way to assist your compatibility decisions, with our Chemical Resistance Test Kit (p/n 173610). This kit contains our most popular head plates and elastomer valves materials. These are actual production parts in current use, so they offer the best test subjects possible. For each material, two parts are supplied – one for resistance testing, the other as a comparison reference. Simple instructions will guide you through the static soak test process.

SUMMARY

In a typical fluidic system, component lifetime will be influenced by several variables beyond simple compatibility of the liquid media, including chemical concentration, liquid temperature, operating pressure, flow rate, and exposure to abrasive materials. A static soak test cannot, therefore, replace a long-term validation test with a pump running in a real system under system parameters. But, a static soak test is well suited as part of an initial screening to identify and eliminate materials which are clearly incompatible with expected liquids.